At present, the electronic industry uses hot gas techniques, precise machining techniques and mechanical removal (chiseling) techniques for non-destructively removing microelectronic integrated circuits (IC's) and other similar microelectronic components, such as staked fasteners, from substrates following epoxy cure. The microelectronic components are removed during upgrades, repair and replacement, or substrate substitution or reuse. In some of the microelectronic component systems, the components have screws (staked fasteners) to aid in securing the component to a substrate. Typically, the screws can be secured by epoxy. The edges of the component can also be bonded by an epoxy, making removal difficult because of the epoxy bond. The three removal techniques mentioned above also have drawbacks.
The use of hot gas may heat the integrated circuit or other similar microelectronic component and the substrate to a temperature in excess of 300 C. This could cause damage to the microelectronic component, thus negating any subsequent use of the component or integrated circuit. Additionally, the excessive temperature could damage other similarly positioned microelectronic components, and in the worst case scenario, the substrate itself could be severely damaged, causing an expensive loss of either the substrate or all components mounted on the substrate.
Very precise machining techniques can be exact enough to remove any surrounding, cured epoxy that secures a microelectronic component to the substrate. However, the machining would require, in addition to exact machining tools and methods, a very precise vacuum wand or draw system with sufficient vacuum controls to prevent debris from flying off and damaging any adjacent microelectronic components or integrated circuits.
Mechanical chiseling is difficult because it requires significant force to be exerted on a small, exactly machined chiseling blade. The excess force exacted on the blade to remove the cured epoxy commonly damages neighboring devices. Mechanical removal techniques also require relatively large forces to be exerted against the substrate, which can damage adjacent components and the substrate itself. This would defeat the purpose of reusing the substrate and associated microelectronic components.
There is, therefore, a need to permit non-destructive integrated circuit and similar microelectronic component removal to permit reuse of those components. If these microelectronic components could be removed successfully without damaging the components themselves, then the substrate could also be reused for other applications. This could create an economic benefit when electronic systems are upgraded, repaired and exchanged.